1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright 2017 Analog Devices Inc.
4 * Author: Lars-Peter Clausen <lars@metafoo.de>
5 */
6
7 #include <linux/err.h>
8 #include <linux/export.h>
9 #include <linux/slab.h>
10 #include <linux/module.h>
11
12 #include <linux/iio/iio.h>
13 #include <linux/iio/consumer.h>
14 #include <linux/iio/hw-consumer.h>
15 #include <linux/iio/buffer_impl.h>
16
17 /**
18 * struct iio_hw_consumer - IIO hw consumer block
19 * @buffers: hardware buffers list head.
20 * @channels: IIO provider channels.
21 */
22 struct iio_hw_consumer {
23 struct list_head buffers;
24 struct iio_channel *channels;
25 };
26
27 struct hw_consumer_buffer {
28 struct list_head head;
29 struct iio_dev *indio_dev;
30 struct iio_buffer buffer;
31 long scan_mask[];
32 };
33
iio_buffer_to_hw_consumer_buffer(struct iio_buffer * buffer)34 static struct hw_consumer_buffer *iio_buffer_to_hw_consumer_buffer(
35 struct iio_buffer *buffer)
36 {
37 return container_of(buffer, struct hw_consumer_buffer, buffer);
38 }
39
iio_hw_buf_release(struct iio_buffer * buffer)40 static void iio_hw_buf_release(struct iio_buffer *buffer)
41 {
42 struct hw_consumer_buffer *hw_buf =
43 iio_buffer_to_hw_consumer_buffer(buffer);
44 kfree(hw_buf);
45 }
46
47 static const struct iio_buffer_access_funcs iio_hw_buf_access = {
48 .release = &iio_hw_buf_release,
49 .modes = INDIO_BUFFER_HARDWARE,
50 };
51
iio_hw_consumer_get_buffer(struct iio_hw_consumer * hwc,struct iio_dev * indio_dev)52 static struct hw_consumer_buffer *iio_hw_consumer_get_buffer(
53 struct iio_hw_consumer *hwc, struct iio_dev *indio_dev)
54 {
55 size_t mask_size = BITS_TO_LONGS(indio_dev->masklength) * sizeof(long);
56 struct hw_consumer_buffer *buf;
57
58 list_for_each_entry(buf, &hwc->buffers, head) {
59 if (buf->indio_dev == indio_dev)
60 return buf;
61 }
62
63 buf = kzalloc(sizeof(*buf) + mask_size, GFP_KERNEL);
64 if (!buf)
65 return NULL;
66
67 buf->buffer.access = &iio_hw_buf_access;
68 buf->indio_dev = indio_dev;
69 buf->buffer.scan_mask = buf->scan_mask;
70
71 iio_buffer_init(&buf->buffer);
72 list_add_tail(&buf->head, &hwc->buffers);
73
74 return buf;
75 }
76
77 /**
78 * iio_hw_consumer_alloc() - Allocate IIO hardware consumer
79 * @dev: Pointer to consumer device.
80 *
81 * Returns a valid iio_hw_consumer on success or a ERR_PTR() on failure.
82 */
iio_hw_consumer_alloc(struct device * dev)83 struct iio_hw_consumer *iio_hw_consumer_alloc(struct device *dev)
84 {
85 struct hw_consumer_buffer *buf;
86 struct iio_hw_consumer *hwc;
87 struct iio_channel *chan;
88 int ret;
89
90 hwc = kzalloc(sizeof(*hwc), GFP_KERNEL);
91 if (!hwc)
92 return ERR_PTR(-ENOMEM);
93
94 INIT_LIST_HEAD(&hwc->buffers);
95
96 hwc->channels = iio_channel_get_all(dev);
97 if (IS_ERR(hwc->channels)) {
98 ret = PTR_ERR(hwc->channels);
99 goto err_free_hwc;
100 }
101
102 chan = &hwc->channels[0];
103 while (chan->indio_dev) {
104 buf = iio_hw_consumer_get_buffer(hwc, chan->indio_dev);
105 if (!buf) {
106 ret = -ENOMEM;
107 goto err_put_buffers;
108 }
109 set_bit(chan->channel->scan_index, buf->buffer.scan_mask);
110 chan++;
111 }
112
113 return hwc;
114
115 err_put_buffers:
116 list_for_each_entry(buf, &hwc->buffers, head)
117 iio_buffer_put(&buf->buffer);
118 iio_channel_release_all(hwc->channels);
119 err_free_hwc:
120 kfree(hwc);
121 return ERR_PTR(ret);
122 }
123 EXPORT_SYMBOL_GPL(iio_hw_consumer_alloc);
124
125 /**
126 * iio_hw_consumer_free() - Free IIO hardware consumer
127 * @hwc: hw consumer to free.
128 */
iio_hw_consumer_free(struct iio_hw_consumer * hwc)129 void iio_hw_consumer_free(struct iio_hw_consumer *hwc)
130 {
131 struct hw_consumer_buffer *buf, *n;
132
133 iio_channel_release_all(hwc->channels);
134 list_for_each_entry_safe(buf, n, &hwc->buffers, head)
135 iio_buffer_put(&buf->buffer);
136 kfree(hwc);
137 }
138 EXPORT_SYMBOL_GPL(iio_hw_consumer_free);
139
devm_iio_hw_consumer_release(struct device * dev,void * res)140 static void devm_iio_hw_consumer_release(struct device *dev, void *res)
141 {
142 iio_hw_consumer_free(*(struct iio_hw_consumer **)res);
143 }
144
145 /**
146 * devm_iio_hw_consumer_alloc - Resource-managed iio_hw_consumer_alloc()
147 * @dev: Pointer to consumer device.
148 *
149 * Managed iio_hw_consumer_alloc. iio_hw_consumer allocated with this function
150 * is automatically freed on driver detach.
151 *
152 * returns pointer to allocated iio_hw_consumer on success, NULL on failure.
153 */
devm_iio_hw_consumer_alloc(struct device * dev)154 struct iio_hw_consumer *devm_iio_hw_consumer_alloc(struct device *dev)
155 {
156 struct iio_hw_consumer **ptr, *iio_hwc;
157
158 ptr = devres_alloc(devm_iio_hw_consumer_release, sizeof(*ptr),
159 GFP_KERNEL);
160 if (!ptr)
161 return NULL;
162
163 iio_hwc = iio_hw_consumer_alloc(dev);
164 if (IS_ERR(iio_hwc)) {
165 devres_free(ptr);
166 } else {
167 *ptr = iio_hwc;
168 devres_add(dev, ptr);
169 }
170
171 return iio_hwc;
172 }
173 EXPORT_SYMBOL_GPL(devm_iio_hw_consumer_alloc);
174
175 /**
176 * iio_hw_consumer_enable() - Enable IIO hardware consumer
177 * @hwc: iio_hw_consumer to enable.
178 *
179 * Returns 0 on success.
180 */
iio_hw_consumer_enable(struct iio_hw_consumer * hwc)181 int iio_hw_consumer_enable(struct iio_hw_consumer *hwc)
182 {
183 struct hw_consumer_buffer *buf;
184 int ret;
185
186 list_for_each_entry(buf, &hwc->buffers, head) {
187 ret = iio_update_buffers(buf->indio_dev, &buf->buffer, NULL);
188 if (ret)
189 goto err_disable_buffers;
190 }
191
192 return 0;
193
194 err_disable_buffers:
195 list_for_each_entry_continue_reverse(buf, &hwc->buffers, head)
196 iio_update_buffers(buf->indio_dev, NULL, &buf->buffer);
197 return ret;
198 }
199 EXPORT_SYMBOL_GPL(iio_hw_consumer_enable);
200
201 /**
202 * iio_hw_consumer_disable() - Disable IIO hardware consumer
203 * @hwc: iio_hw_consumer to disable.
204 */
iio_hw_consumer_disable(struct iio_hw_consumer * hwc)205 void iio_hw_consumer_disable(struct iio_hw_consumer *hwc)
206 {
207 struct hw_consumer_buffer *buf;
208
209 list_for_each_entry(buf, &hwc->buffers, head)
210 iio_update_buffers(buf->indio_dev, NULL, &buf->buffer);
211 }
212 EXPORT_SYMBOL_GPL(iio_hw_consumer_disable);
213
214 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
215 MODULE_DESCRIPTION("Hardware consumer buffer the IIO framework");
216 MODULE_LICENSE("GPL v2");
217